[PATCH] kprobes: clean up resume_execute()

Clean up kprobe's resume_execute() for i386 arch.

Signed-off-by: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index 7a59050..b40614f 100644 (file)
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -362,10 +362,10 @@ static void __kprobes resume_execution(struct kprobe *p,
                struct pt_regs *regs, struct kprobe_ctlblk *kcb)
 {
        unsigned long *tos = (unsigned long *)&regs->esp;
-       unsigned long next_eip = 0;
        unsigned long copy_eip = (unsigned long)p->ainsn.insn;
        unsigned long orig_eip = (unsigned long)p->addr;
 
+       regs->eflags &= ~TF_MASK;
        switch (p->ainsn.insn[0]) {
        case 0x9c:              /* pushfl */
                *tos &= ~(TF_MASK | IF_MASK);
@@ -375,9 +375,9 @@ static void __kprobes resume_execution(struct kprobe *p,
        case 0xcb:
        case 0xc2:
        case 0xca:
-               regs->eflags &= ~TF_MASK;
-               /* eip is already adjusted, no more changes required*/
-               return;
+       case 0xea:              /* jmp absolute -- eip is correct */
+               /* eip is already adjusted, no more changes required */
+               goto no_change;
        case 0xe8:              /* call relative - Fix return addr */
                *tos = orig_eip + (*tos - copy_eip);
                break;
@@ -385,27 +385,21 @@ static void __kprobes resume_execution(struct kprobe *p,
                if ((p->ainsn.insn[1] & 0x30) == 0x10) {
                        /* call absolute, indirect */
                        /* Fix return addr; eip is correct. */
-                       next_eip = regs->eip;
                        *tos = orig_eip + (*tos - copy_eip);
+                       goto no_change;
                } else if (((p->ainsn.insn[1] & 0x31) == 0x20) ||       /* jmp near, absolute indirect */
                           ((p->ainsn.insn[1] & 0x31) == 0x21)) {       /* jmp far, absolute indirect */
                        /* eip is correct. */
-                       next_eip = regs->eip;
+                       goto no_change;
                }
-               break;
-       case 0xea:              /* jmp absolute -- eip is correct */
-               next_eip = regs->eip;
-               break;
        default:
                break;
        }
 
-       regs->eflags &= ~TF_MASK;
-       if (next_eip) {
-               regs->eip = next_eip;
-       } else {
-               regs->eip = orig_eip + (regs->eip - copy_eip);
-       }
+       regs->eip = orig_eip + (regs->eip - copy_eip);
+
+no_change:
+       return;
 }
 
 /*